The triquetra has been found on runestones in Northern Europe and on early Germanic coins. It presumably had pagan religious meaning and it bears a resemblance to the Valknut, a symbol associated with Odin.
G Scale Trains are usually referred to as Garden Trains since they are the largest of the model trains and are used outdoors as well as indoors.
Z scale is the fastest growing scale in model railroading today. Some Z scale manufacturers offer briefcase layouts; entire track layouts with landscape, buildings, and a power supply all in a briefcase. These are high-end executive toys that sell for around $1,000.